In general, a dialysis machine is used as a substitute for the natural kidney functions of a human body. As such, the dialysis machine cleanses the blood of the natural accumulation of bodily wastes and separates the wastes from the blood outside of or extracorporeally of the body. The separated wastes are discharged, and the cleansed blood is returned to the body.
The wastes are separated from the blood in a dialyzer. The dialyzer includes an internal housing which is separated by a porous membrane into a blood side or compartment and a dialysate side or compartment. The blood removed from the patient flows through the blood side of the dialyzer. A prepared solution of dialysate is passed through the dialysate side of the dialyzer. The wastes from the blood pass through the membrane by osmosis, ionic transfer or fluid transport into the dialysate and, depending upon the type of dialysis treatment, desirable components from the dialysate may pass in the opposite direction through the membrane and into the blood. The transfer of the wastes into the dialysate cleanses the blood while allowing the desired components from the dialysate to enter the bloodstream.
As is apparent, the dialysis machine must be properly operated to perform effective dialysis in a safe and reliable manner. With the blood of the patient being removed and handled outside of the patient's body in an extracorporeal flow path, care must be taken that the treatment progresses safely and as is intended according to the dialysis prescription for the patient. With the patient's blood and the dialysate separated only by the dialyzer membrane, it is apparent that numerous safety concerns must be satisfied on a continual and reliable basis.
In the past most dialysis machines have provided very little opportunity for customized usage. With the complexity of the functions which must be performed during treatments, and the potential severity of the consequences if those functions are net properly and safely performed, the vast majority of the functionality of the machine has been preset. The operator was allowed to select only a few parameters, such as the target loss of weight or fluid volume to be removed from the patient during treatment, and the elapsed time for the treatment. More recently available dialysis machines have provided more optional parameters for operators to control. For example, more recent dialysis machines have provided the capability for the operator to vary the concentration of chemicals in the dialysate over the time period of the treatment.
One of the reasons for the lack of control over many of the operating parameters has been due to the complexity of the treatment and the potential for error if the operating characteristics are not carefully chosen. Dialysis machine manufacturers may have simply been unwilling to relinquish the control over the functionality of the system by making more of the operating parameters available for modification by the operator of the machine. Traditional medical treatment has also concerned itself with only a limited number of the functional aspects of the dialysis treatment. As a consequence, the typical dialysis machine provides only a limited number of operational parameters which the operator may select for modification, and only a limited number of operational parameters which can be displayed for monitoring the progress of the treatment and monitoring the condition of the patient.
Recent developments in the knowledge of the medical aspects of dialysis treatment have suggested that better results may be available by optimizing parameters during treatment that have not typically been optimized. Even from a non-therapeutic standpoint, many dialysis machine operators have begun to believe that more effective and safe treatment can be applied by closer and more individualized monitoring of the patient and the progress of the machine.
The relatively fixed functionality of the typical dialysis machine has proved to be a detriment to future modification of operating parameters. The operating parameters which the operator may desire to modify may not be modified due to the fixed functional aspects of the machine. If it is possible to modify certain parameters, the number of parameters which can be varied may be relatively limited. Further still, considerable difficulty may be encountered in attempting to modify those variables, particularly in computer-based dialysis machines. Few if any operators or maintenance personnel have the software programming capabilities that may be required to execute such changes. The inability to make these changes has potentially limited the treatment to levels which are not optimal to the patient. Furthermore the inability to vary significantly the operating parameters has discouraged attempts to optimize dialysis treatments, both from the therapeutic standpoint and from the patient comfort standpoint.
Similarly, the relatively fixed monitoring and information displaying capabilities of the dialysis machines have increased the responsibilities of the operator during treatments. In many circumstances, the information which the operator needs to monitor is not readily available, or is presented only in an awkward or difficult manner to easily comprehend. As a result the operator may not feel completely comfortable during the treatment, or the operator will avoid careful monitoring of the patient and machine conditions.
These and other considerations have contributed to the evolution of the present invention which is summarized below.